Heretofore it has been known to utilize potentiometers and rheostats for purposes of controlling voltage and/or power to a controlled device. Sound and lighting systems are principal examples of systems which may be controlled by such devices. Previously known potentiometers and rheostats, used hereinafter interchangeably, have utilized a wiper upon a linear resistor to tap off a selected voltage which might be used directly to control the desired system or be used for application to a control circuit to effect the desired control. Previously known rheostats have lacked durability due to mechanical wear which increases electronic noise with age. Further, the electromechanical nature of such rheostats or controllers has been such as to generate undesired noise which could be coupled to surrounding systems. Additionally, dirt, corrosion, or the like has had a tendency to build up on such known controllers, necessitating frequent cleaning to prevent their ultimate inoperability.
It has also been found that the physical size of previously known controllers has been excessive, the power requirements and/or desired sensitivity dictating such size. Furthermore, with the advent of computer controlled systems, the need for a more direct way of interfacing humanly controlled systems to the controlling computer is apparent.
Accordingly, there is a need in the art of a controller or rheostat which eliminates the electromechanical contact of previous controllers, which is impervious to adverse effects from the ambient, and which is highly reliable in operation while allowing construction within accepted standards of physical size.